Improved sabot for rotating shot and shell



Patented June 10, 1856.

Witnesses:

Inventor: *4

ILFETERS PHOTQLITHOGRAPHER, \VASNWGTON. D C.

W. w. HUBBELL.

Sabots and Wads,

2 Sheets-Sheet 2 No. 15,075. Patented June 10, 1856.-

Witnesses:

MPETERs, PHOTmLITNOGRAPMER; WASHINGTON, D C.

in which" the cannon.

of the cannon.

smooth iron spherical shot or shell, with the cartridge; without elongating the metal or its velocity; without increasing the strain 011 the gun; without diminishing the diameter of out of the said smooth-bored cannon, in order -to increase its precision of flight, and cause the front or heaviest side, 8, of this sizedwindiJNTTnn STATES PATENT @rricn.

XVILLIAM \V. HUBBELL, OF PHILADELPHIA, PENNSYLVANIA.

IMPROVED SABOT FOR ROTATING SHOT AND SHELL.

" Specification forming part of Letters Patent No. 5,075, dated June 10, 1516.

In all whom it may concern:

Be it known that 1, WILLIAM XV. HUBBELL, ofthecity of Philadelphia, and State of Pennsylvania, have invented a new and useful Improvement in the Construction of Sabots for Rotating Shot and Shell; and I do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the annexed drawings, making part hereof,

Figure 1 is a side view of the sabot and shot and their respective windages and relation to each other and to the bore of the cannon. Fig. 2 is a view of the back part of the sabot, and its position and windage in the bore of Fig. 3 is a front view of the shot and its form and extent of windage in the bore In the different figures like letters refer to like parts.

The nature of my invention consists in the construction of a light wooden rotating sabot, to be presently described, adapted to the smoothbored cannon, and common-sized usual form and size of windage, and the ordinary position of the surface of the shot in and upon the bore of the cannon, such as are now in general service in the United States Navy and fortifications, and which sabot, by employing the usual amount of projecting and windage gases, respectively,intl1e best manner, causes the said shot or shell with such contact with the bore, form and size of windage, and present weight of inetal to be releived of its friction, and to rotate on an axis coincident with its line of flight, with the least proportional expenditure of power or gas; without any additional escapement or reaction of gas through the windage, without grooving or making any change in the cannon, or causing any new resistance to the forward action of the changing the form of the shot without increasing the weight ofthe shot; without diminishing the shot'or reducing its weight; but to rotate it unchanged, relieved of its friction-bearing,and

age and form of shell or shot to continue in front with increased certainty, without impairing its extent or curvature of range or degree of force or execution. diameter than the bore, allowing of a considerable reduction in the weight, and held in a socket in the end of a carrier of paper with helical threads or grooves in its surface, the rotating motion being by the gases bearing upon the helical surfaces of the threads, and the depth of the thread one-quarter the diameter of the projectile, and the helical grooves opentoward the conical or ogival part of the projectile, so as to afford an escape for the gases, have been used. threads being one-quarter the diameter of the shot, and open, gives the diameter of the shot lessened to two-thirds the diameter of the bore, and a considerable reduction of weight, makes the windage annular in form, and equal to one-third the diameter of the bore, or onesixth all around the shot, through which the gas escapes from, and reacting on the helical grooves. Such shot, therefore, is 4.266 inches in diameter in a 6.40 inch bore or thirty-two pounder gun. -Its windage is 1.66 inch all around the shot. Its carrier is made of paper or expansiblesubstance, equal in length to its diameter, to fit and support the weight of the shot in the gun, but is not intended nor adapted to rotate the common shot of fifteen one-hundreths of an inch windage, without change of its diameter, weight, windage, or position in or relation to the bore of the cannon. Also, sabots fitted with tongues to grooves made in the bore of the cannon, to rotate the sabot by the resistance of the grooves,havebeen made, but not without cutting or rifiingthe smooth surface and weakening and straining the cannon, and increasing the friction, and such sabot made of wood is not intended nor adapted to operate in smooth-bored cannon. Also, shot with oblique surfaces on the hinder part, formed by a body of iron or heavy metal as part of the shot, have been made, and intended to rotate with precis-ion,but not without increasing the weight of the shot, changing its form, increasing its friction in the gun, expending more power to give it the same Velocity, increasing the strain 011 the gun, and not without being intended to take the place of or throw out of use the common spherical shot now in general service. Also, I have discovered by actual experiment that the weight Shot of a less The depth of these of the metal used to form such oblique surfaces on the hinder part of the shot does, in its flight, by the superior momentum due to its greater weight, turn the hinder part of the shot to foremost in the flight, and, in changing, force or direct the shot out of its trueline of flight.

N o sabot before my invention has ever been made to relieve the friction of and to rotate the common spherical shot with common form and extent of windage and usual position and bearing of its weight in the cannon, without either increase or diminution of its size or weight or change of form,without grooving the gun, without any additional expenditure of power or gas, or increase of friction or resistance, and out of smooth-bored cannon.

My sabot is so constructed as to adapt it to all the existing conditions, relations, and elements ofthe round shot and shells and smoothbored cannon now in general use, and by means of the usual amount of projecting and windage gases, respectively, to rotate the shot with the least proportional power and friction, and without impairing its existing advantages nor the safety and-endurance of the cannon.

To describe the construction and adaptation of my invention, this shot being spherical and large, the forward and hindermost portions have curved surfaces, Fig. 1, descending both ways to the central line of gin vity, c, and the bearing-point c, which is important in relation to the construction and action of my sabot upon the curved surface (I to relieve the friction, which will be presently described. The extent of power by which the smooth surface V V of the shot or shell is laid hold of to overcome the inertia of the shot and rotate it, is thewhole pressure and friction of the rotating power on the solid bowl of the sabot against the surface of the shot without any additional or new resistance or escape or reaction of gas 'to cause rotation. The oblique surfaces Z Z, four in number, on the back part of the wooden body of the sabot, and on the'oblique surfaces m m on the horizontal ribs 7c of this body, tending to rotate in the same direction as the surfaces Z Z, receiving the whole projectingpower to both, cause the same rotation of the sabot and the friction on the shot by means of the solid body of wood 13 i between these sets of faces and the bowl 0 0, which, at the center t, is free one-twentieth of an inch from the surface of the shot for one-third of its diameter, I bearing the bowl with the whole rotating-power against the outer iron surface, V V, of the shell or shot, and causes both the greatest friction on and the speediest and strongest rotation and projection of the shot. Also, while this action is taking place, and in aid thereof, a portion of the gas from the cartridge at B B rushes forward through the lower opening, Figs. 1 rand 2, jj, between the body t 'i of the sabot 5 and bottom 1 of the bore, as indicated by the *arrow n, and presses against the curved surfaCe' d-of' the shell, close to its bearing-point 0 on the bore, andinearly under the line or center of gravitation e of the spherical form curving to said point, and raises this shot, or relieves the bore of its weight by means of this winda-ge, gas, or power alone, and thus speedily relieves the sabot of the office of overcom ing this friction in its givingrotation to the shot or shell in the cannon without any new form of or additional winda-ge or escapement of gas or transfer of the weight and friction of the shot to be borne by the sabot on the bore, or use of power through the windage other than usual in projecting this size, weight, and windage of spherical shot or shell from such gun. The arrow f indicates the direction of rotation in the flight of the shot on the axis h h.

The proper proportions of the shot or shell and sabot in the smooth bore of the cannon are as follows: Vindage of the shot in the cannon equals fifteen one-hundredths of an inch; diameter of the sabot across the ribs q (1 equals the same as the diameter of the shot; total length of the sabot from the extreme point p to back 1) equals two-thirds of the diameter of the shot; depth of the bowl V V of the sabot equals one-third of the diameter of the shot, with.05 inch free space at the centert for one-third of its diameter; thickness of the body of the sabot, from the base of the bowl t to the extreme back part, a, equals one third of the diameter of the shot, less .05 inch; width of the ribs k in front each equals onefourth of the diameter of the shot, and four ribs in number; obliquity of the angled side m of each rib equals twelve degrees; obliquity of the angled sides Z of the hinder part of the sabot equals fifty degrees, and the same in number as the ribs; depth of the open space j of the sabot, between its ribs and behind the bearing-point c of the shot on the bore, equals fifteen one-hundredths of an inch, being the same as the extreme windage of the shot at the top of the bore. The sides r r of the ribs and hinder part of the sabot opposite the oblique faces are parallel with the axis 9 g of the gun, and coincident or in plane with each other on the same and on opposite sides, and with a plane through the axes h h of the sabot and shot. They may be made three, five, or seven in number, and not in plane on oppo 'site sides.

The arrows a: y indicate the directions of the forces of rotation and projection, both attained by the sudden pressure of the power of the cartridge on the oblique faces and the friction caused by the pressure of the solid bowl by the whole of the same force against the surface of the shell, with the relief of the friction of the shot on the under side of the bore by the gas which passes through the lower wind- .age of the sabot at q against the lower curved surface, d, of the shotthereby suddenly causing the easy rotation and projection of the shot or shell, which by its m' s inertia continues such rotation in its flight, with the least proportional expenditure of power or gas; without any additional escapement, or reaction of gas through the windage, or transfer of its weight and friction to the bore by or upon the sabot; without grooving or weakening the cannon, or causing any new resistance to the forward action of the cartridge; without elongating the metal or changing the form of the shot; without increasing the weight of the shot; without diminishing its velocity; without increasing the strain on the gun, or its friction on the bore; without diminishing the diameter of the shot, or reducing its Weight; without reducing or impairing its extent or degree of curvature of range, or degree of penetrating force or execution, or powderspace for explosionand thus increase its precision of flight, and cause the front or heaviest side of this spherical body to continue in front with increased certainty, by means of this construction of sabot utilizing or employing the usual amount of the projecting and windage escaping gases, respect ively, to this end in the best manner.

The sabot must be made of light, tough of the body i t, to strengthen it.

Vhat I claim is- The construction of wooden sabot, substantially as described, adapted to relieve the friction of and easily rotate the smooth spherical shot or shell of the common diameter, conse' quent weight, form, and extent of windageand bearing of its weighton the bore, out of itsusual size of smooth-bored cannon, under the conditions as described.

Wu. w. HUBBELL.

lVit nesses:

Pnnnosn FELL, CHARLES D. FREEMAN. 

